WASHINGTON (Reuters) -- Terrorist groups lack the capability to launch a damaging Internet-based attack on the United States but foreign governments are probably behind many online spying attempts, FBI officials said on Wednesday.

Al Qaeda and other militant groups do not have the ability to disable power plants, airports and other "critical infrastructure" through the Internet, said FBI Assistant Director Louis Reigel, who heads the enforcement agency's Cyber Division.

"There's nothing on my desk today or the director's desk that would cause any concern today," Reigel told reporters in a briefing at FBI headquarters.